1. Field of the Invention
The present invention relates, in general, to a semiconductor device and a method for fabricating the same. Particularly, the present invention relates to a semiconductor device with a bilayer conductive wiring structure and without any contact for interconnecting different types of conductive wirings, thereby contributing to the high integration of a semiconductor device. Also, the present invention is concerned with a method for fabricating the semiconductor device such that the production yield is improved.
2. Description of the Prior Art
High integration of semiconductor devices is necessarily accompanied by complicated conducting wirings, which connect one device with another. The complicated conducting wirings generally form a multilayer structure in which many contacts are formed to interconnect the wirings on each layer with each other, deleteriously affecting the topology of the overall structure of the final semiconductor devices. Such topology gives rise to a decrease in the production yield and acts as a main impediment which inhibits the further integration of semiconductor devices.
High integration of semiconductor devices also forces the channel length of a MOSFET to be shortened. In order to minimize the channel length, p type MOSFETs take advantage of a p type impurity-doped polysilicon gate. For an n type MOSFET an n type impurity-doped polysilicon gate is utilized. In such case, additional connecting lines are prepared in order for one gate line to connect the p type polysilicon with the n type polysilicon. In addition, since the connecting lines are contacted at the boundary region between the polysilicons with different impurity types, the area for the contact must be secured on designing semiconductor devices.
Besides, the different type gate lines can be electrically connected with each other only after carrying out an implantation process of respective impurities two times and a contact process. Consequently, this prior art procedure is complicated and the semiconductor devices obtained by it are difficult to highly integrate because of the large area occupied by the contact regions.